Roofing systems of buildings with low pitch or flat roofs typically use waterproof membranes to prevent water from entering into the building. Large sheets of such membranes are welded or glued to one another, depending on the material of the membrane, to form continuous sheets that cover the entire surface of the roof.
Membranes require termination of one kind or another at least at a perimeter edge of the roof Because the perimeter edge of the roof is an area that experiences forces that act in different directions as well as being an area where wind vortices create low pressure regions, the roof is prone to expansion and contraction as well as wind failure in this area. Parapet walls and sheet metal gutters, gravel stops and fascia finishes can leak in this area damaging conventional perimeter membrane terminations. Typical edge termination practices such as; nailers, termination bars, reinforced membrane strips and fasteners are prone to failure for mainly two reasons: first, the pulling of the membrane due to high winds eventually tears the membrane at the stress concentration points created by the small discrete or non-uniform areas of membrane retention; and second, moisture finds its way to the boards in which the retaining features are embedded, causing rotting that eventually results in the fasteners coming loose from the boards. Once the membrane is no longer retained at the perimeter of the roof, winds can easily peal it away allowing water from rain and snow to enter the building through the unprotected roof.
Accordingly, there is a need in the art for improvements in retention of waterproof roof membranes, particularly at the perimeter of a roof.